Sanguinarine, a natural benzophenanthridine alkaloid, has been shown to possess anticancer activity in vitro and in vivo. In the present study, we demonstrated that sanguinarine caused a dose-dependent inhibition of growth in HeLa and SiHa human cervical cancer cells, i.e., 2.43 µmol/l (IC50) in HeLa cells and 3.07 µmol/l in SiHa cells. Cell cycle analysis revealed that sanguinarine significantly increased the sub-G1 population, from 1.7 to 59.7% in HeLa cells and from 1.7 to 41.7% in SiHa cells. Sanguinarine caused a dose-dependent decrease in Bcl-2 and NF-κB protein expression and a significant increase in Bax protein expression. Our findings indicate that sanguinarine as an effective anticancer drug candidate inhibits the growth of cervical cancer cells through the induction of apoptosis.